Heat-insulating board composed of cereal straw.



UNITED sTaTns PATENT oianrcia.

JAMES E. LAPPEN, OT WINONA, MINNESOTA, ASSIGNOR TO UNION FIBRE COMPANY, 015 WINONA, MINNESOTA, A CORPORATION OF MINNESOTA.

HEAT-INSULATING BOARD COMPOSED OF CEREAL STRAW.

NO Drawing.

To all whom it may concern.

Be it known that I, JAMES E. LAPPEN, a citizen of the United States, residing at Vinona, in the county of \Vinona and State of Minnesota, have invented a new and useful Heat-Insulating Board Composed of Cereal Straw, of which the following is a specification.

My invention relates to a heat insulating board composed of cereal straw.

The object of my invention is to provide a self-sustaining board for insulating purposes composed entirely of cereal straws such as those of wheat, oats, rye or barley. Felt, or boards for this purpose, have here tofore been made of flax, hemp or jute, or some mixture of such long fibered plants with a less expensive vegetable tissue. It has been supposed, however, that the fiber of the cereal straws above named was too short and weak when unmixed with longer fibers to produce a self-sustaining felt of homo geneous texture, having a practical degree of resiliency and tensile strength. My present board, however, which is composed of such cereal straws, is self-sustaining, possesses a high degree of insulating value and is adequately coherent and flexible to render it desirable for insulating purposes. Because of the cheapness 0f the raw materialsused, it is far more economical than a similar board composed of the longer vegetable fibers.

The cereal straw, either wheat, oats, rye or barley, should be partly degummed, so as to loosen the ligneous material surrounding the fibers. Such degumming may be accom- Specification of Letter: Patent.

Application filed December 27, 1915.

Patented May 8,11 91 Z.

Serial No. 68,661.

plished in any one of the usual methods. I preferto treat it for that purpose by an alkaline process. While thematerial remains wet from such alkaline treatment, it is hackled or scutched under water by means of a toothed wheel co-acting with a toothed stationary bedplate. This may be accomplished by means of a device such as that illustrated in my Patent No. 1,158,245, of October 26. 1915. The action of the teeth of this machine not only removes av large part of the ligneous 1110i gummy material inci'usting the longer fibers of the straw, but also pulps the chaff without breaking the long fibers and leaves such fibers in good condition for the felting process. The wet fibers are then a glomerated to a felt with the residuum of gummy matter and the pulp from the chaff for a binder, and finally tamped or pressed into board form by any of the usual means employed for that purpose in felting the products of flax straw.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

As a new article of manufacture, a thermal insulating board composed of long, partially purified fibers of cereal straw felted and agglomerated with a binder of the gummy components of said straw and constituting a coarsely porous and coherent body.

hereof, I have hereunto subscribed my name to this specification.

JAMES E. LAPPEN. 

